Chong Pooi Koon and Ranjeetha Pakiam

Malaysia's Air Force chief denied saying Flight 370 was tracked deviating from its path into Malacca Strait, adding to the confusion surrounding the search for the missing plane, which entered its fifth day.

''It would not be appropriate for the Royal Malaysian Air Force to issue any official conclusions as to the aircraft's flight path until a high amount of certainty and verification is achieved,'' General Rodzali Daud said in a statement. He was referring to a reports that he said cited him as saying an air base detected the plane in Malacca Strait.

This handout photograph released by the Indonesian Air Force on March 12, 2014 shows the view from an Indonesian Air Force military surveillance aircraft on March 11 over the Malacca Strait, a passageway between Indonesia and Malaysia, searching for the missing Malaysia Airlines flight MH370. Photo: Indonesian Air

Malaysia is widening the area being combed for signs of the plane to include the Malacca Strait. That's roughly in the opposite direction as the intended course of the Beijing-bound Boeing 777-200 over the Gulf of Thailand.

The absence of wreckage has kept alive various theories about the plane's disappearance, from an accident to hijacking to sabotage. The plane's position when it vanished may be in doubt, said Richard Bloom, director of terrorism and security studies at Embry-Riddle Aeronautical University in Arizona.

''When flying over water, in my opinion there is no such thing as 100 per cent accurate technology of any kind,'' Mr Bloom said in an interview. ''Not all of that information may have been getting back. It could have been distorted by occurrences still to be determined.''

Media reports of radar data showing the jet at the Malacca Strait, to the north-west of Malaysia's capital, is at odds with official announcements that Flight 370 was nearing Vietnamese airspace when controllers lost all contact.

Advertisement

Flight 370's planned route carried it in a northerly direction from Kuala Lumpur, and would have taken it on into China. From its last known position in the Gulf of Thailand, reaching the Malacca Strait would have required a reversal of course executed without detection by ground-based radar.

Chinese Premier Li Keqiang called for more effort in the search, according to a statement. Meanwhile, Vietnam said it was temporarily scaling back its search efforts as it waited for more information from Malaysia.

Dozens of ships and planes from at least 10 countries are helping in the search, which has drawn international attention to the mystery while families of the 239 passengers and crew await news.

Japan is sending a disaster relief team, the Japanese embassy in Malaysia said. ''All ongoing search operations are at the moment being conducted to cover all possible areas where the aircraft could have gone down in order to ensure no possibility is overlooked,'' General Rodzali said.

The aircraft, which disappeared without sending any distress signal, may have made an ''air turn-back'', Malaysian Acting Transport Minister Hishammuddin Hussein said on Sunday. The pilots did not signal trauma or danger before losing radio contact.

The second man travelling on a stolen passport was Delavar Seyed Mohammad Reza, 29, of Iran.

Malaysia is still combing through the passenger manifest and scouring the background of the crew for signs of personal or psychological issues, police said.

The longest period in modern aviation history between an airliner disappearance and initial findings of debris was when Adam Air Flight 574 disappeared off the coast of Indonesia's South Sulawesi - and it was 10 days before debris was found.